A microscopic probe having a sharp apex may be utilized in such cases as measuring of 2-dimensional behaviors of conductive particles on a conductive substrate or to draw lines having a width of less than 0.1 .mu.m by means of tunneling current or field emission current.
Such microscopic probe having sharp apex has been conventionally fabricated through mechanical abrasion or electrolytic abrasion.
In the case of mechanical abrasion, a metallic wire cut to a desired length is ground by means of a grinder and the like for mechanical polishing.
In the case of electrolytic abrasion, the tip of a tungsten wire 1 having diameter of about 0.5 mm is first dipped in a dilute potassium hydroxide (KOH) solution 2 as shown in FIG. 1. A DC voltage derived from a DC power supply 4 is then applied across the tungsten wire 1 and an electrode 3, which will have the surface of the tungsten wire 1 in the solution 2 abraded. Since abrasions proceeds much faster near the surface of the solution, the portion of the tungsten wire 1 in contact with the surface of the still solution is abraded to a spindle shape and eventually cut. By quickly turning off the electricity at the moment of the cut of the wire, which can be known from a sudden change in current, a microscopic tungsten probe having a sharp apex can be obtained.
However, such conventional methods as mentioned above can fabricate probes one at a time and they cannot provide densely populated microscopic probes. The reason for this is that conventional mechanical polishing is limited in precision and the electrolytic abrasion has a limitation due to surface tension of the electrolytic solution. Therefore it is not only extremely difficult with these methods to fabricate a microscopic probe but also impossible to fabricate densely populated microscopic probes.
Conventionally, therefore, a single microscopic probe has to be mechanically moved over a substrate surface for scanning measurement or has to draw the same pattern repeatedly, which extremely impairs the efficiency of the work.